EnerGaia - Spirulina media water recycling

The Problem

Global food supply has to double by 2050 to meet the demand of our growing population. Protein sources will be particularly strained. The world must find sustainable alternative protein sources. We believe spirulina is one great choice. It is a microalgae that grows very quickly in pools or tanks of water. We can use seawater as a partial basis to grow spirulina which helps with the sustainability of its water footprint (already much better than traditional protein sources). But to help with the overall water conservation problem, we would like to find a way to reuse the water in our spirulina tanks perpetually by recycling it once it becomes inhospitable for the spirulina to grow due to ion shifts and a buildup of excess metabolites (dissolved organic matter).

Our Proposal

Based on our current research and work with local universities, we believe that a multi-stage water treatment solution will be needed. Its steps would include: removal of solid particles and residual biomass, probably thru some form of filtration; digesting or removing the dissolved organic matter in the water; possibly adjusting or shifting the ion balances; filtering again; sterilization of any micro-organisms.

Our Inspiration

We have been a commercial spirulina producer using our closed tank system for more than 5 years. In Thailand, we are fortunate to have ample supplies of water. But now we are taking our spirulina production system to the developing world as a means to uplift livelihoods and help with rural nutritional health. However, many of these areas are suffering from extreme water scarcity. We therefore are inspired to find a sustainable solution to recycle / reuse over 95% of the water in our tanks.

We Assume that...

the water in the tanks can be treated to become nearly as productive as fresh media to grow spirulina

a low cost solution can be developed to rehabilitate the water that is cost competitive with starting from fresh water and nutrients

Constraints to Overcome

The solution should allow for the reuse of at least 90% of the water. The system should have a spirulina productivity that is at least 90% of the productivity level of new water with fresh nutrient media. The solution should be able to fit on a small footprint of less than 10 square meters if possible. It should also strive to be a low cost solution, which can be defined further if needed.

Current Work

Review water characterization data; validate solution idea or propose alternatives; conceptualize solution idea(s) into pilot system designs; build prototypes and test them at our existing spirulina labs and farms to determine viability; analyze data and pivot if necessary; repeat process until a workable, low-cost solution is obtained

Current Needs

Need technical experts to review our existing water characterization data and conceptual design, provide design inputs and guidance on a testing program. Skills and knowledge include chemical engineering, microbiology, and wastewater treatment expertise (specifically in the reduction of low concentrations of dissolved organic matter and shifting of high salinity and ion loads).